Magnetic wheels are often applied to fitness equipment (e.g. treadmills) as part of dampening structures. To offer optional resistance for the benefit of different operators of the fitness equipment, a controller is required to adjust the resistance of magnetic wheels in the equipment. The present invention has provided an improved controller, which generally comprises a drive motor, variable gear set, tester and cable-driven wheel. A variable gear set and a cable-driven wheel are activated by the drive motor. In the case of rotation, a cable is pulled by the variable gear set to drive the magnetic component of magnetic wheel, while the cable-driven wheel will actuate a cam shaft of the tester, such that the tester can sense the location of resistance and then transmit a signal to control panel.
However, a typical controller for a magnetic wheel has problems in practice. First, when the drive motor is activated during initial assembly of the magnetic wheel and controller, the cable used to link cable-driven wheel and magnetic wheel has a slight adjusting error because of tightness. Before the cam shaft of tester is rotated in a preset location, the cable has already pulled the magnetic component of the magnetic wheel to this location owing to this error. In such a case, manual fine adjustment of the cable shall be required (note: the cable is often fitted with a micrometer adjusting screw), leading to delay of assembly and lower efficiency in the manufacturing process.
Another problem lies in the transmission between the drive motor and variable gear set. The output shaft of the drive motor is generally provided with a screw, which permits engagement with a first gear set of the variable gear set. Since a screw end is typically suspended without any support structure, axial thrust of a worm gear likely results in unstable deflection, unsmooth operation and mechanical damage or even shorter service life.
Thus, to overcome the aforementioned problems of the prior art, it would be an advancement in the art to provide an improved structure that can significantly improve the efficacy.
To this end, the inventor has provided the present invention of practicability after deliberate design and evaluation based on years of experience in the production, development and design of related products.